Improvement in stons-cttttino machines



dinde-1i gnent @met dimite.

FREDERICK 'IOWNSEND, OF ALBANY, NEW YORK.

Letters Patent .N 95,955, dated Octlfber I9, 1869.

IMPROVEMENT IN STONE-CUTTING- MACHINES.

The Schedule referred to in these Lette'nPatent and making part o'f the same To all whom it may concern-.-

head, having four chisels applied to it, and having a portion of` its face-plate broken away.

This iuventiop relates to au improvement ou the stone-quarrying machine, forwhich I made application for Letters Patent of the United States on the 6th day of August, 1869.

My object is to prevent chisels or drills from dragging upon the stone after the blows have been given, by so applying -the chisels to vtheir rotary head that they will respectively continue the work immediately after the blows are struck, in the directionv ofthe blows, and iu the line of their axes, as will be hereinafter explained.

To enable others skilled iu the art to understand my invention, 'I will describe its construction and operation.

In the accompanyingr drawings- A represents a circular chisel-carrying head, which consists of twociicular disks, secured rigidly together, with ehisellguides b b confined between them.

This cam O -is prevented from rotating with the head A, vby seeming it in au'y suitable manner to the frame upon which the shaf't'B has its bearings; and, as the head A'isrotated, the said cam retracts the chisels successively, and at proper points releases them, and allows their springs to force them downward upon the stone, as will be hereinafter explained.

In my application for Let-ters Patent, referred to, the chisels were applied to their rotary head, so as to radiate' from the axis thereof', which arrangement caused the chisels to drag upon the stone after every blow until they were moved around far enough to be lifted t'rom.the stone.

I new arrange the chisels tangent to a circle described withiu the circumference of the head A, so that the chisels are at right angles to each other if' four are used, as shown by the drawing, or they may be arranged in the form of' a polygon if more than four chisels are used. f

Each chisel E is applied between parallel guides b b, so as to have endwise motion, and around each chisel a spring, c, is coiled, one end of whichacts against lug e, andthe other end acts against a shoulder at the opposite end of a slot made through head A. Thus it will be seen that the operation of' each spring c is to thrust outwardly its chisels, and give the blows.

Each chisel E is provided with a vibrating retracting arm, D, which is pivoted to the head A at a, and which has its free eud fitted loosely into a recess made into the head of -the,chisel, and on that edge of' each arm D, which is next the cam C, a toe, d, is

formed, which -is held against the periphery of' said cam by the spring c of the chisel, acted' upon by said am) I).

It will be seen, from the above description, that during the rotation of the head A, u the direction indica-ted by the arrow in the drawing, the chisels E will be successively retracted by the cam O and arms D, and that as the chisels successively arrive at the proper point-iu their revolution for striking the stone, the toes d will leave that point of' the cam which has the greatest radiusfand allow-spring c to effect the blows by'their recoil.

In practice the cam c will be adjustable around its shaft B,.so that the chisels may be caused to strike at different angles with respect to the plane of' the stone which is being chanuelled.

I do not. claim broadly, under ythis petition, the use of the chisels which receive rotary and endwise motions, as this feature is described and claimed by me in my application for Letters Patent, filed August 6, 1869, above referred to; nor do I confine myself` to the use of vibrating arms I), as media through which cam C operates to retract the chisels, as other means.

1otary'head,aud operated substantially as and for the purpose desciibed.

Witnesses:

LEONARD KIP, Rurus G. BEABDsLEn.

FREDK'. TOWNSEN D. 

